A typical passive autofocus optical lens system includes an optical system, one or more image sensors, a controller and a motor to automatically focus the optical lens on a selected object. There are various methods of providing autofocus including active and passive autofocus systems and methods. Active autofocus systems measure distance to the subject independently of the optical system, and subsequently adjust the optical lens system to provide correct focus. These measurements can be made with displacement sensors which can be ultrasonic, laser or infrared. Passive methods determine correct focus by performing passive analysis of the image entering the optical system. Passive autofocus can be achieved by systems and methods of phase detection and contrast detection autofocus. Camera manufacturers typically have to choose between phase detection and contrast detection in designing camera autofocus optical systems.